Convergence of Mechanical and Electronics in Automotive Design

11 Aug 2022 • 5 minute read

Someone once said, “Mechanical engineers design the automotive machine, electrical engineers design the navigation brains, and civil engineers design the roadways.” Implied here could be the idea that these engineering disciplines work separately. But increasingly, designing in isolation—at least for mechanical and electrical engineers—is insufficient to develop modern products. And they are converging in ways that mandate multiphysics analysis of traditionally siloed design disciplines. To overcome design challenges, engineering leaders need to proactively bring these teams together.

To be sure, electronic system designers are not going to suddenly start designing enclosures or mechanical fans. Still, innovative products require that all their electronics be analyzed in the context of the environment in which they run. That means mechanical systems and electronics are more closely related and interdependent than ever. The growing market for electronic conveniences in automobiles is an excellent opportunity for mechanical and electrical engineers to leverage each other’s skills to build innovative products.

Sending the Right Signals

One of the significant challenges in automotive design is that things can get hot. Increasing electronics for autonomous driving, high-speed communications, and infotainment, must be designed to survive or be protected from these thermal sources. Whenever you move electrons quickly, electro-thermal simulations become a top priority to ensure components do not prematurely fail or wear out before warranty. Electric vehicles (EVs) are still in their infancy and can use multiphysics system analyses to digitally optimize designs to match traditional car design industry knowledge.

Furthermore, consider the countless features in an automotive design that rely on signal and power integrity: pedestrian detection, adaptive cruise control, blind-spot monitoring, lane-departure warning, automatic high-beam technology, and others. These features must operate in a synchronous fashion; therefore, testing must be done simultaneously.

Remember that a signal carries data from one system or network to another. EVs produce hundreds of electromagnetic/electrical signals or currents. Ensuring that these signals don’t interfere with or degrade one another to an excessive degree is mission-critical. EVs demand a power and signal integrity analysis, which is paramount to ensure proper function and longevity. A typical automobile now boasts more than 1,000 chips within its frame. While most are employed for infotainment, autonomous driving and related safety are a fast-growing second in terms of chip usage.

Another consideration to include is that some signals interact only with the internal EV system, and some interact with external elements such as 5G networks. Because the signals are so interdependent, they must be simulated simultaneously to ensure safe, secure, and correct operation, including the coexistence with the numerous signals at hand.

Sleek and Quiet - Energy and Range

A primary consumer criterion for EVs is range, so maximizing the distance an EV can travel on one charge is an important design consideration. Energy efficiency in internal combustion engine (ICE) vehicles is no less important.

Other interesting facets of modern automotive design are noise, vibration, and harshness. There is always something moving and shaking in a car, and reducing weight while using new materials creates new design challenges.

However, acoustic simulation and testing are crucial in EV design because they are quieter due to the lack of ICE noise. Road noise and wind turbulence can critically affect the EV driver experience. The sound of the wind going around the side-view mirrors is very apparent in an EV. Tire noise not noticed previously now becomes a potential problem. Wind and road noise have a huge impact on the perception of quality. These factors and many others that had little impact on ICE vehicles significantly impact EVs. Therefore, designs must be reconsidered to ensure an optimal EV driver experience.

The increasingly interdependent relationship between mechanical and electrical components in an electric vehicle may herald a day when building innovative products means both mechanical and electronics engineers work closely together—becoming the norm—throughout the entire product development process.

Concurrent Multiphysics Analysis

Multiphysics interactions are becoming more complex as companies continually strive for increased performance. Design complexity for mechanical designers may even be approaching the level of complexity that electronics designers have faced for years. This exponential increase in design complexity—both in electrical and mechanical designs—demands a holistic approach to the analysis of the entire system.

The exponential growth of complexity in devices, from miniaturization, form factors, and space constraints to Wi-Fi, Bluetooth, performance optimization, and multiple physics, produce significant design challenges. And more and more products leverage communication to the outside world by some form of a radio signal, be it 5G, Bluetooth, Wi-Fi, or other standards.

Radios are among the most challenging components to design since every design aspect interacts with everything else. It is not just the shape of the antenna that is critical, but also the shape of every connector, package pin, printed circuit board (PCB) trace, enclosure, and even where people sit and interface with the technology.

When you analyze such designs for optimization, you must concurrently analyze (or simulate) how each facet of a design affects the entire spectrum of analysis because each electronic component affects the others, including how mechanical components and enclosures affect performance. Siloed simulations for testing are not enough.

Could lessons learned by electronics engineers regarding the simulation of multiphysics interactions, which often need to be tested simultaneously, help mechanical engineers?

The Only Constant Is Change

The convergence of mechanical and electronic design is just getting underway, and today’s engineering leaders need to break down their team siloes to further optimize their products. To avoid costly design errors, mechanical engineering teams must go beyond simple handoffs or just throwing designs over the wall to electrical design teams. Staying aligned with the entire team is critical, but more is required. Mechanical, electrical, and software teams need to become co-designers, working closely on every facet of the vehicle’s design because of the interdependent relationship of mechanical, electrical, and algorithmic elements.

Connected technologies demand connected teams. Few products involve mechanical-only designs. More and more products are built with sensors, software, and electronics. All designs—not just mechanical ones—must interact seamlessly. This tight interaction means that today’s products must be tested as a single unit, not separately, not only to speed the testing and optimization process but to ensure its accuracy.

The days of working in siloed design teams may soon be history—and perhaps that’s a good thing. Discussing and sharing results will no longer be enough. All engineering stakeholders (mechanical, electrical, and software) work as a singular unit as co-designers. The right hand always knows what the left hand is doing, each guiding the other along the way to more highly innovative and optimized designs.